.xm-back-top {
  position: fixed;
  right: 100px;
  bottom: 50px;
  width: 40px;
  height: 40px;
  color: rgba(0,0,0,.65);
  font-size: 14px;
  font-variant: tabular-nums;
  line-height: 1.5715;
  list-style: none;
  font-feature-settings: "tnum";
  cursor: pointer;
  .content {
    width: 40px;
    height: 40px;
    overflow: hidden;
    color: #fff;
    text-align: center;
    background-color: rgba(0,0,0,.45);
    border-radius: 20px;
    transition: all .3s cubic-bezier(.645,.045,.355, 1);
    &:hover {
      background-color: rgba(0,0,0,.6);
    }
    .icon {
      width: 14px;
      height: 16px;
      margin: 12px auto;
      background: url("../../../../assets/images/back-top.png") 100%/100% no-repeat;
    }
  }
}
